Radio Impacts Due To Group Triggering And Paging And Solutions For Group Triggering And Paging

ABSTRACT

A method includes transmitting a paging indicator indicating to user equipment assigned to one or more groups that the user equipment are to attempt to receive paging messages including paging information targeted to at least one of the one or more groups; and transmitting in a channel the paging information in the paging messages. Another method includes receiving a paging indicator indicating a user equipment is to attempt to receive paging messages including paging information targeted to at least one of one or more groups; and receiving from a channel the paging information in the paging messages. A method includes sending a request message to user equipment assigned to one or more groups, the request message comprising an indication to cause the user equipment to read device trigger information in a system broadcast message; and sending the device trigger information in the system broadcast message.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/290,279, filed on Nov. 7, 2011, the disclosure of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

This invention relates generally to wireless networks and, morespecifically, relates to paging user equipment using the wirelessnetworks.

BACKGROUND

This section is intended to provide a background or context to theinvention disclosed below. The description herein may include conceptsthat could be pursued, but are not necessarily ones that have beenpreviously conceived, implemented or described. Therefore, unlessotherwise explicitly indicated herein, what is described in this sectionis not prior art to the description in this application and is notadmitted to be prior art by inclusion in this section.

The following abbreviations that may be found in the specificationand/or the drawing figures are defined as follows:

-   3GPP third generation partnership project-   APN access point name-   AS access stratum-   DRX discontinuous reception-   DT device trigger-   eNB base station, evolved Node B (also, eNodeB)-   E-UTRAN evolved UTRAN (LTE)-   FDD frequency division duplex-   GGSN gateway GPRS support node-   GPRS general packet radio service-   GSM global system for mobile communications-   HLR home location register-   ID identification-   IMSI international mobile subscriber identity-   LTE long term evolution-   LTE-R LTE railways-   MBMS multimedia broadcast/multimedia service-   MBSFN multi-media broadcast over a single frequency network-   MME mobility management entity-   MMEC MME code-   MTC machine-type communication-   M2M machine-to-machine-   PBP paging block periodicity-   PCCPCH primary common control physical channel-   PDCCH physical downlink control channel-   PDN packet data network-   PI page indicator-   PICH paging indicator channel-   PF paging frame-   PMR public mobile radio-   PO paging occasion-   P-RNTI paging RNTI-   RAN radio access network-   RN radio network-   RNTI radio network temporary identifier-   RRC radio resource control-   SACCH slow assisted control channel-   SAE system architecture evolved-   SCCPCH secondary common control physical channel-   SGSN serving GPRS support node-   SIB system information block-   SFN system frame number-   SMS short message service-   S-TMSI SAE TMSI-   TMSI temporary mobile subscriber entity-   VGCS voice group call service-   UE user equipment-   UMTS universal mobile telecommunications system-   U-RNTI UTRAN-RNTI-   UTRAN universal terrestrial radio access network

User equipment (UE) originally were primarily wireless devices such ascellular phones. Now, UEs are used in railway systems for voice and datacommunications between, e.g., the driver, staff, and the control centerand for train positioning, fleet management, remote diagnostics, andtrain control. LTE-R (long term evolution-railway) is being defined tofurther address bandwidth and other issues. UEs are also used for publicmobile radio, which supports technologies such as group calling orinstant calling (e.g., push-to-talk). Furthermore, there are UEs thatsupport machine type communications (MTC), such as sensors that canprovide information to a central facility as in the railway system. MTCcommunication also includes machine-to-machine (M2M) communications,where one “machine” such as a sensor communicates with another “machine”such as a controller. Many of these UEs are arranged in groups. Forinstance, certain types of sensors may be assigned to one group, orcertain personnel could be assigned one group. Therefore, instead ofhaving primarily point-to-point communications, modem wirelesscommunications systems also have to support UEs that are arranged ingroups.

As an example, the VGCS (voice group call service) enables a callingservice subscriber or calling dispatcher to establish a voice group callto destination subscribers belonging to a predefined group call area andgroup ID (identification). Applications for voice group call servicestypically involve multiple group members in a small group call area, forwhich the VGCS should provide spectrum efficient solutions. The VGCS isapplicable to, e.g., LTE-R and PMR.

Relative to MTC, for many M2M applications, there may be an interest tohave a poll model for communications between MTC devices and the MTCserver. This may be because the MTC user (i.e., a person using servicesprovided by the MTC server) wants to be in control of communication fromMTC devices, and does not allow MTC devices to randomly access the MTCserver. Also, for applications where normally the MTC devices initiatecommunications, there may occasionally be a need for the MTC server topoll data from the MTC devices.

A primary technique for accessing groups of UEs is through group paging.It would be beneficial to provide group paging, e.g., while stillallowing UEs the ability to reduce power.

SUMMARY

In an exemplary embodiment, a method includes transmitting a pagingindicator indicating to user equipment assigned to one or more groupsthat the user equipment are to attempt to receive one or more pagingmessages including paging information targeted to at least one of theone or more groups; and transmitting in a channel the paging informationin the one or more paging messages.

In another exemplary embodiment, a computer program product includes acomputer-readable medium bearing computer program code embodied thereinfor use with a computer, the computer program code includes: code fortransmitting a paging indicator indicating to user equipment assigned toone or more groups that the user equipment are to attempt to receive oneor more paging messages including paging information targeted to atleast one of the one or more groups; and code for transmitting in achannel the paging information in the one or more paging messages.

In a further exemplary embodiment, an apparatus includes means fortransmitting a paging indicator indicating to user equipment assigned toone or more groups that the user equipment are to attempt to receive oneor more paging messages comprising paging information targeted to atleast one of the one or more groups; and means for transmitting in achannel the paging information in the one or more paging messages.

In an additional exemplary embodiment, an apparatus includes one or moreprocessors and one or more memories including computer program code. Theone or more memories and the computer program code are configured to,with the one or more processors, cause the apparatus to perform:transmitting a paging indicator indicating to user equipment assigned toone or more groups that the user equipment are to attempt to receive oneor more paging messages comprising paging information targeted to atleast one of the one or more groups; and transmitting in a channel thepaging information in the one or more paging messages.

In an additional exemplary embodiment, a method includes receiving, at auser equipment assigned to one or more groups, a paging indicatorindicating to the user equipment that the user equipment is to attemptto receive one or more paging messages including paging informationtargeted to at least one of the one or more groups; and receiving from achannel the paging information in the one or more paging messages.

In another exemplary embodiment, a computer program product includes acomputer-readable medium bearing computer program code embodied thereinfor use with a computer, the computer program code comprising: code forreceiving, at a user equipment assigned to one or more groups, a pagingindicator indicating to the user equipment that the user equipment is toattempt to receive one or more paging messages including paginginformation targeted to at least one of the one or more groups; and codefor receiving from a channel the paging information in the one or morepaging messages.

In a further exemplary embodiment, an apparatus includes means forreceiving, at a user equipment assigned to one or more groups, a pagingindicator indicating to the user equipment that the user equipment is toattempt to receive one or more paging messages comprising paginginformation targeted to at least one of the one or more groups; andmeans for receiving from a channel the paging information in the one ormore paging messages.

In an additional exemplary embodiment, an apparatus includes one or moreprocessors, and one or more memories including computer program code.The one or more memories and the computer program code are configuredto, with the one or more processors, cause the apparatus to perform:receiving, at a user equipment assigned to one or more groups, a pagingindicator indicating to the user equipment that the user equipment is toattempt to receive one or more paging messages comprising paginginformation targeted to at least one of the one or more groups; andreceiving from a channel the paging information in the one or morepaging messages.

An additional exemplary embodiment includes an apparatus including oneor more processors and one or more memories including computer programcode. The one or more memories and the computer program code configuredto, with the one or more processors, cause the apparatus to perform:sending a request message to user equipment assigned to one or moregroups, the request message comprising an indication to cause the userequipment to read device trigger information in a system broadcastmessage; and sending the device trigger information in the systembroadcast message.

A further exemplary embodiment includes an apparatus including one ormore processors and one or more memories including computer programcode. The one or more memories and the computer program code configuredto, with the one or more processors, cause the apparatus to perform:receiving, at a user equipment assigned to one or more groups, a requestmessage comprising an indication to cause the user equipment to readdevice trigger information in a system broadcast message; and receivingthe device trigger information in the system broadcast message.

BRIEF DESCRIPTION OF THE DRAWINGS

In the attached Drawing Figures:

FIG. 1 is a block diagram of an exemplary system in which the exemplaryembodiments may be practiced.

FIG. 2 is an example of alternating group paging cycles and legacypaging cycles.

FIG. 3 is a block diagram of a method performed by a network (e.g., basestation) for group triggering and paging.

FIG. 4 is a block diagram of a method performed by a user equipment forgroup triggering and paging.

DETAILED DESCRIPTION OF THE DRAWINGS

Before proceeding with description of exemplary embodiments, it ishelpful at this point to describe certain communication systems, sincethese systems are referenced below. The exemplary embodiments herein areuseful in UTRAN (universal terrestrial radio access network-long termevolution) and E-UTRAN (evolved UTRAN), although E-UTRAN will bedescribed herein. A specification of a communication system known asE-UTRAN (also referred to as UTRAN-LTE, universal terrestrial radioaccess network-long term evolution, or as E-UTRA) is 3GPP TS (technicalstandard) 36.300, V8.12.0 (2010 04), “3rd Generation PartnershipProject; Technical Specification Group Radio Access Network; EvolvedUniversal Terrestrial Radio Access (E UTRA) and Evolved UniversalTerrestrial Access Network (E-UTRAN); Overall description; Stage 2(Release 8)”. This system may be referred to for convenience as LTERel-8. In general, the set of specifications given generally as 3GPP TS36.xyz (e.g., 36.211, 36.311, 36.312, etc.) may be seen as describingthe LTE system. Release 9 (Rel-9) versions of these specifications havebeen published, including 3GPP TS 36.300, V9.7.0 (2011-3). Release 10(Rel-10) versions of these specifications have also been published,including 3GPP TS 36.300, V10.4.0 (2011-06). Work on Rel-11 is ongoingand should be finished sometime in 2012 for RAN1 (physical layer).Rel-12 work has not started as of the drafting of this disclosure, butstudies are currently proceeding for what will be included in Rel-12.Thus, there are multiple releases of communication systems for userequipment (e.g., wireless devices communicating at least over cellularfrequencies) and base stations, and these releases describeimplementation details for user equipment and the communication systems.The exemplary embodiments below are primarily directed to future(relative to the current date) releases of the communication systems, asnew paging techniques are provided.

Before addressing in more detail problems with current techniques forgroup paging and exemplary embodiments to reduce or eliminate theseproblems, it is helpful to describe an exemplary system in which theexemplary embodiments may be practiced. FIG. 1 shows such an exemplarysystem. In FIG. 1, N UEs 110 are in wireless communication with anetwork 100. Only UE 110-1 is described in more detail herein; the otherUEs 110 are assumed to be similar. The user equipment 110-1 includes oneor more processors 120, one or more memories 125, and one or moretransceivers 130 interconnected through one or more buses 127. The oneor more transceivers 130 are connected to one or more antennas 128. Theone or more memories 125 include computer program code 123. The one ormore memories 125 and the computer program code 123 are configured to,with the one or more processors 120, cause the user equipment 110 toperform one or more of the operations as described herein. Each UE 110communicates with eNB 220 via link 111.

The UEs 110 are divided into a number of groups 190 in this example. UEs1 through M are in group 1 (190-1); UEs M and M+1 are in group 2(190-2); and UEs M+1 through N are in group 3 (190-3). Each of the UEs Mand M+1 therefore belong to two groups.

The entity 220 includes one or more processors 150, one or more memories155, one or more network interfaces (N/W I/F(s)) 161, and one or moretransceivers 160 interconnected through one or more buses 157. The oneor more transceivers 160 are connected to one or more antennas 158. Theone or more memories 155 include computer program code 153. The one ormore memories 155 and the computer program code 153 are configured to,with the one or more processors 150, cause the entity 220 to perform oneor more of the operations as described herein. The one or more networkinterfaces 161 communicate over a network such as the networks 170 and131. Two or more entities 220 communicate using, e.g., network 170. Thenetwork 170 may be wired or wireless or both.

In an LTE example, the entity 220 is an eNB and the network 170 mayimplement, e.g., an X2 interface. The wireless network 100 may include anetwork control element (NCE) 205 that may include MME/SGWfunctionality, and which provides connectivity with a further network,such as a telephone network and/or a data communications network (e.g.,the Internet). The eNB 220 is coupled via a network 131 to the NCE 250.The network 131 may be implemented as, e.g., an Si interface. The NCE250 includes one or more processors 175, one or more memories 171, andone or more network interfaces (N/W I/F(s)) 180, interconnected throughone or more buses 185. The one or more memories 171 include computerprogram code 173. The one or more memories 171 and the computer programcode 173 are configured to, with the one or more processors 175, causethe NCE 250 to perform one or more operations described herein.

In an example for UTRAN, the element(s) 220 may include a Node B (NB)and a radio network controller (RNC). The element(s) 250 may include aserving GPRS support node (SGSN), home location register (HLR), and/or aGGSN, as examples. The network 131 may be implemented as an Iuinterface.

The computer readable memories 125, 155, and 171 may be of any typesuitable to the local technical environment and may be implemented usingany suitable data storage technology, such as semiconductor based memorydevices, flash memory, magnetic memory devices and systems, opticalmemory devices and systems, fixed memory and removable memory. Theprocessors 120, 150, and 175 may be of any type suitable to the localtechnical environment, and may include one or more of general purposecomputers, special purpose computers, microprocessors, digital signalprocessors (DSPs) and processors based on a multi-core processorarchitecture, as non-limiting examples.

In general, the various embodiments of the user equipment 110 caninclude, but are not limited to, cellular telephones such as smartphones, personal digital assistants (PDAs) having wireless communicationcapabilities, portable computers having wireless communicationcapabilities, image capture devices such as digital cameras havingwireless communication capabilities, gaming devices having wirelesscommunication capabilities, music storage and playback appliances havingwireless communication capabilities, Internet appliances permittingwireless Internet access and browsing, tablets with wirelesscommunication capabilities, as well as portable units or terminals thatincorporate combinations of such functions.

As described above, a primary technique for accessing groups of UEs isthrough group paging. The following use cases involve group paging andare to be addressed in 3GPP based on operator and customer requirements.These use cases have a very high priority due to the expanding marketsrequiring group paging. For instance, M2M is a growing market, and manyGSM operators expect to be able to trigger millions of devicesnationwide, to access devices like smart meters. As another example, theLTE-R market will be an evolving market that will need such a solutionas well.

An exemplary case from an M2M perspective is as follows. UE(s) thatbelong to a group should be triggered together. For instance, a networkmight request devices 1000 to 1999 (using IDs) to report back certaininformation. Also, the UE(s) can belong to multiple groups. Requirementsto address this use case are as follows. The network should provide amechanism to send a broadcast message within a particular geographicarea to a MTC group, e.g., to wake up the MTC devices that are membersof that MTC group. Only MTC devices of the target group configured toreceive the broadcast message will recognize the broadcast message. Thegeographic area for the broadcast may be a cell sector, a cell, or agroup of cells. Furthermore, verification of receipt of a broadcastmessage is not necessary.

An exemplary use case from the LTE-R, PMR perspectives is as follows.The UE(s) should be triggered together, to request for them to join agroup call. Since the group calls can happen simultaneously, UE(s) thatbelong to multiple groups can receive trigger indications from differentgroups at the same time. It is then up to the UE(s) to decide which callthe UE(s) needs to join. Requirements to address this use case are asfollows. The information “To which group or group(s) a subscriberbelongs” is stored as part of a user's subscription. This is staticinformation. The subscriber could belong to more than one group. Thesubscriber is notified of group calls and the decision is left up to thesubscriber on which call he or she desires to join.

Thus, a group-paging scheme needs to be designed with a proper trade-offbetween the resulting paging load, the paging capacity of the network,and the power-consumption implications to the UE from monitoring grouppaging, all this preferably scalable also with the number of groupsapplicable to the network on one hand, and to the UE on the other.

It is known that group paging can be used to page the UE(s) that belongto a group. Group paging can be performed using shared TMSI (temporarymobile subscriber entity) calculated using the group ID and allocated bythe network.

There has been some discussion in RAN2 (radio access network 2, aworking group in 3GPP) about how to enable group paging. One proposal isthat MTC could be organized into groups which are represented by groupID. The MTC devices monitor the P-RNTI (paging-radio network temporaryidentifier) in PDCCH (physical downlink control channel) at pagingoccasions (POs) computed by either its own IMSI (international mobilesubscriber identity) or group ID. Other discussions have presented RAN2proposals by introducing the group paging. One proposal is to calculatethe PO based on the group ID. The other proposal includes group ID in apaging message. All the proposals reuse existing mechanisms to calculatepaging frames and paging occasions except that group ID is utilizedinstead of UE individual ID. However, if MTC device belongs to multiplegroups, i.e., is associated with multiple group IDs, the MTC deviceneeds to wake up at multiple POs in order to detect the paging messagesdestined to any of its group IDs and this will drain the UE batteryquickly.

In UTRAN, group paging functionality is described in specification25331, section 8.6.3.13, “Group release information”. More particularly,3GPP TS 25.331 V10.4.0 (2011-06), section 8.6.3.13. This functionalityallows targeting UEs in groups (based on the variable U_RTNI) to releasethe RRC connection. This feature, however, does not provide any specifichandling of the paging indication procedure: the UE still monitors thepaging indicator according to its IMSI.

The instant invention solves these problems through, e.g., an optimizedmechanism that will only trigger the devices that belong to the groupand are intended to be triggered by the network. The mechanism shouldnot impact other (non-paged) UE(s) (i.e., more than the impact caused bypaging other UEs today). It is expected that the UEs will be pagedtogether when the UEs are in idle mode, or CELL_PCH, URA_PCH states incase of UTRAN in order for the network 100 to be able to trigger theUEs. Additionally, this disclosure also proposes a mechanism to delivertrigger information to multiple UEs.

In an exemplary embodiment, it is proposed to incorporate one or more ofthe following modifications in UTRAN and E-UTRAN.

(1) Use only a common paging indicator for all groups to notify allgroups, or in some possible embodiments for a subset of groups, tonotify of an actual forthcoming group-paging message. This indicatorwill be in addition to the legacy paging mechanism. The existing pagingsubframes will be reused in an exemplary embodiment to avoid issues withpossible MBSFN subframes used, e.g., for MBMS, relay. As is known, relayis a scenario where a relay node connects as an intermediate node with adonor eNB and UEs. Since for inband relay (see 3GPP TS 36.814), UEsconnecting to the RN only listen to non-MBSFN subframes, therefore, thegroup paging message should not be sent in those MBSFN subframes so thata UE is able to receive the group paging.

(2) Alternate group paging cycles with legacy paging cycles. Design theDRX cycle 240 of the group paging cycle 245 (see FIG. 2) for the groupand the DRX cycle 280 of the legacy paging cycle 280 in such a way thatthe UE is waking up the same number of times as the UEs with legacypaging DRX cycles would be waking up if only performing legacy DRXcycles.

In order to achieve this, UE should monitor its legacy paging occasionevery two DRX cycles (in an exemplary embodiment), rather than per DRXcycle, and in the DRX cycle where the UE does not monitor the legacypaging occasion, the UE monitors the group paging occasion. The term“paging occasion” has slightly different meanings in UMTS and LTE.However, the term “paging occasion” in both UMTS and LTE refers at somepoint to the position of the element (e.g., a paging indicator,typically a bit) the UE should monitor for paging. In UMTS, this isdivided into two parameters: PO (Paging Occasion) for the SFN and PI(Page Indicator) for the position in the radio frame. See 3GPP TS25.304, section 8.3. More specifically, a legacy paging occasion in UMTSis the SFN of the PICH frame where the UE monitors its paging indicator;put another way, the SFN of the PCCPCH frame in which the PICH framebegins, the UE monitors the group paging occasion. The definition in LTE(see 3GPP TS 36.304 section 7.1) is as follows: One Paging Occasion (PO)is a subframe where there may be P-RNTI transmitted on PDCCH addressingthe paging message. So the term PO in LTE is a concept for a subframerather than a SFN. The radio frame, which may contain one or multiplepaging occasion(s) is called “paging frame (PF)”.

(3) In order to ensure that UE does not drain its battery by waking uptoo many times for different group paging, the following exampletechniques for group paging are proposed.

a. The position of the paging indicator and its corresponding frameposition in the group paging cycle 245/DRX cycle 240 will change intime. Based on a specific algorithm, based for example on the SFNnumber, the page indicator (PI) and Paging Occasion (PO) (into which thepaging indicator is placed) are calculated so that the paging indicatoris spread in the paging indication space. That is, the paging indicatorwill be placed somewhere in the paging indication space, at a locationdefined by the algorithm and the corresponding PI and PO. The pagingindicator space is, in an exemplary embodiment, the frame location inthe group paging cycle 245/DRX cycle 240 and the location of the pagingindicator inside the frame. It is noted that varying the position of thepaging indicator and its corresponding frame position saves power bysaving collisions between UEs listening to the same paging indicatorspace, as those UEs not listening at a particular group paging cycle 245(or a portion thereof) can be in a low power mode.

b. The “common paging indicator for all group paging” embodiment couldprovide an indicator, e.g., one new bit in the paging message,indicating that in this and/or a following paging cycle, one or moregroups is/are being paged in the paging occasion defined by the sharedS-TMSI. Only after detecting this bit, a UE monitoring for any grouppaging would need to check also the paging occasion defined by theshared S-TMSI in that/those paging cycles. Alternatively, the indicatorin the paging message can be a few bits so that each bit can indicatethat a certain type of group paging will follow. For instance, one bitcould indicate MTC group paging, one bit could indicate LTE-R grouppaging, one bit could indicate PMR group paging, and the like. It isnoted that shared S-TMSI is calculated as follows: <MMEC>+<uniqueidentifier within the MME>, where MMEC is MME code, and the sharedS-TMSI is used to assign a common identifier to all the devices (UEs)that belong to a group. In an exemplary embodiment herein, it isproposed to calculate a single group paging occasion for UE(s) thatbelong to multiple groups. Many different approaches are suggestedherein to accomplish this optimally. One possibility is also calculatinga paging occasion based on shared S-TMSI. That is, if a set of n bitsare allocated commonly for all groups by the MME/SGSN, then replace IMSIin the current formula (shown below for Paging Occasion) to calculatepaging occasion with the common 10 bits of S-TMSI.

c. The eNB indicates via SIB separate group paging parameters, which areindependent of shared S-TMSI. Such group paging parameters couldindicate group paging cycle(s) (could be absent if same as legacy pagingcycle) and group paging occasion(s). Upon detecting the information, theUE does not calculate the group paging occasions based on its group ID(e.g., as defined by the S-TMSI); instead, the UE shall monitor thegroup paging occasion (e.g., within the group paging cycle) as indicatedby eNB if the UE belongs to at least one paging group.

A simple example is the eNB indicates subframe #4 (number 4) of thefirst frame #0 in every group paging cycle is a group paging occasion.If a group paging cycle indication is not provided by eNB, then the UEassumes the group paging cycle and paging frame are the same as that forlegacy paging cycle and paging frames. But the UE shall monitor subframe#4 of the first frame in the paging frames for group paging.

Some variants are listed below to avoid UEs reacting to the group pagingat the same time when a large number of UEs belong to at least one MTCgroup:

i) Duplicate the group paging cycle, i.e., group paging cycle+offsettingthe group paging cycle by K subframes. In this example, more resourcesare consumed than with single group paging cycle, but UEs may select tomonitor one of the multiple group paging cycles so as to distribute UEsin time.

ii) Define more than one group paging cycle indicated from eNB, e.g.,group paging cycle #1 (number one) applies to groups #1-10 (numbers onethrough 10); group paging cycle #2 applies to groups #11-20. In thisexample, the UEs could be distributed somehow, but at the cost of morepower consumption because each UE needs to monitor more paging occasionsif the UE belongs to more than one group.

iii) Define more than one group paging cycle and/or paging occasionsindicated from eNB based on the type of the group paging, e.g., grouppaging occasion (PO) #0 for MTC group paging, group PO #1 for LTE-Rgroup call, group PO #4 for PMR group paging, and the like. In thisexample, the UEs could be distributed depending on the type of its groupand avoids monitoring the group pagings which are not relevant to thegroup to which the UE belongs.

How the above mentioned three proposals are accomplished for E-UTRAN andUTRAN are explained below.

Regarding the E-UTRAN paging indicator and DRX cycle lengthdetermination, examples of these are presented below.

In an exemplary embodiment, DRX cycles for regular (legacy) paging andgroup paging could be allocated in a dedicated UE message, e.g., ATTACHACCEPT, TAU ACCEPT. The MME/SGSN (e.g., MME 250 in FIG. 1; the SGSN isnot shown) should provide the DRX cycle to the eNB. Logic (e.g., as partof computer program code 123, 153) within the UE 110 and the eNB 220should be modified such that the higher of the two DRX values (commonDRX cycle in the broadcast message, DRX cycle in the dedicated UEmessage) are used for the paging cycle. This is mainly to ensure the UEis not waking up more often than necessary. E-UTRAN paging frames (PF)and paging occasions (PO) are defined in TS 36.304 section 7. See, e.g.,3GPP TS 36.304 V10.1.0 (2011-03), section 7, “Paging”.

Another approach for group paging determination is as follows. In asimple technique, group paging can obey the defaultPagingCycle alreadybroadcast in SIB2 (for defaultPagingCycle, see, e.g., 3GPP TS 36.331;3GPP TS 25.304 section 8.3 and 3GPP TS 25.331 section 6.3.2), whosepossible values range between, e.g., 320 ms (milliseconds) to 2.56 s(seconds), as well as nB also broadcast in SIB2 (see section 7 of 3GPPTS 36.304). In another example, the group-paging indicator can bebroadcast (and monitored) in the PF and PO defined by UE_ID=0. In afurther example, the group paging indicator can be realized, e.g., as anextension bit or extension bits in the paging RRC message. In yetanother example, the transmission of the group paging indicator meansthat in the ongoing paging period, defined as changing whenever SFN moddefaultPagingCycle turns 0, a group will be paged using group S-TMSI inplace of UE-specific IMSI (also in PF, PO determination). Reference tothe ongoing period works for all groups, because UE_ID=0 implies thefirst PF and the first PO of the paging period, i.e., the indicator willappear before all other PFs and POs in the paging period.

Concerning UTRAN paging indicator and DRX cycle length determination,examples of this are presented below, and extensions to LTE may easilybe implemented. It is noted for LTE that there may be the possibilityfor a single paging message to have paging information targeted togroup(s) of user equipment and targeted to user equipment on anindividual basis. For instance, in FIG. 1 above, the UE 110-M couldreceive a single paging message having paging information targeted togroup 190-1, group 190-2, and/or to the UE 110-M individually.

In one example, DRX cycles for regular (legacy) paging and group pagingcould be allocated in a dedicated UE message, e.g., ATTACH ACCEPT, RAUACCEPT. SGSN should provide the DRX cycle to the RAN nodes (e.g., eNBs220). Logic within the UE and the RAN should be modified such that thehigher of the two DRX values (common DRX cycle in the broadcast message,DRX cycle in the dedicated UE message) are used for the paging cycle.This is mainly to ensure the UE is not waking up more often than needed.

Examples of formulas include the following. For regular paging, thefollowing exemplary formula may be used:

Paging Occasion={(IMSI div K)mod(DRX cycle length div PBP)}*PBP÷n*2*DRXcycle length+frame offset,

where PBP=paging block periodicity and n=0,1,2 . . . as long as SFN isbelow its maximum value (i.e., n has to be chosen to be within a properrange, e.g., 0 . . . 4095), K is a parameter linked to the number ofSCCPCHs (see 3GPP TS 25.304, section 8.1), and the frame offset isconfigured by the network (e.g., base station 220) and is alreadydefined by specification. The “div” operation returns a quotient fordivision of one number by another. The “mod” (modulo) operation findsthe remainder of division of one number by another. In comparison with aconventional paging occasion scheme, the Paging Occasion formula abovefor regular paging makes a paging occasion occur every other (e.g., 2n)DRX cycle (as shown in DRX cycles 280 in FIG. 2).

The actual page indicator within a paging occasion that the UE shallread is similarly determined based on IMSI. The page indicator to use iscalculated by using the following formula:

PI=DRX Index mod Np,

where DRX index=IMSI div 8192, and Np is described in 3GPP TS 25.304section 8.3 (e.g., Np, for FDD, is the number of page indicators withina frame).

For group paging, the following exemplary formula may be used:

Paging Occasion={n}mod(DRX cycle length div PBP)}*PBP+((2*n+1)*DRX cyclelength)+frame offset,

where n=0,1,2 . . . as long as SFN is below its maximum value. Incomparison with a conventional paging occasion scheme, the PagingOccasion formula above for group paging makes a paging occasion occurevery other (e.g., 2n+1) DRX cycle time (as shown in DRX cycles 240 inFIG. 2). In other words, if the regular paging occasion occurs every“even” (e.g., 2n) DRX cycle 280, then the group paging occasion occursevery “odd” (e.g., 2n+1) DRX cycle 240.

The actual page indicator within a paging occasion that the UE shallread is similarly determined based on SFN. The page indicator to use iscalculated by using the following formula:

PI=(SFN div 2)mod Np.

If desired, more advanced functions can also be used to distribute thepaging occasion/paging index.

In another aspect of the invention, it is proposed to include the devicetrigger information in the broadcast SIB. The device trigger informationcould include a command for the UE, e.g., that the UE needs to connecttowards a certain APN. The device trigger information could, forexample, be an AT (ATtention) command (string). This is sent in orderfor the UE to connect to the network or comply with the instructionprovided. In order to ensure that all the UE(s) are not reading thebroadcast SIB unnecessarily, an exemplary proposal is to optimize thepaging request message by including a device trigger notification bit.If the UE sees this bit, then the UE knows that the UE should read thebroadcast SIB and take appropriate action such as forward theinformation provided in the broadcast SIB to the upper layers. Thefollowing exemplary actions may be taken.

1. The network initiates group paging for shared S-TMSI (i.e., a groupof devices). The network includes a “device trigger notification” bit inthe paging request message.

2. Device trigger information is included in the broadcast SIB, e.g.,SIB #10, 11, or 12. If DT (device trigger) notification was present inthe paging message, the UE 110 reads the corresponding SIB, which isdesigned to include device trigger information (e.g., pre-definedapplication specific command, i.e., “Reporting”, APN, or appID). The AS(access stratum) layer within the UE 110 forwards this to the upperlayer.

3. The UE responds with a service request.

4. Based on the trigger information, the UE takes appropriate action.The UE 110 initiates a PDN (packet data network) connectivity request(if applicable) or responds with a small amount of data (e.g., via SMS,short message service).

Referring now to FIG. 3, FIG. 3 illustrates a block diagram of a methodperformed by a network 100 (e.g., a base station 220) for grouptriggering and paging. Although characterized as a method, theoperations performed in FIG. 3 may also be operations performed by anapparatus, operations performed by code on a computer-readable medium,or means for performing the operations. In block 310, the network 100performs the operation of transmitting a paging indicator indicating touser equipment assigned to one or more groups that the user equipmentare to attempt to receive one or more paging messages comprising paginginformation targeted to at least one of the one or more groups. In block360, the network 100 performs the operation of transmitting in a channelthe paging information in the one or more paging messages. Blocks315-350 are further examples of block 310. Blocks 370 and 380 arefurther examples of block 360.

In block 315, the paging information in the paging message(s) comprisespaging records targeting the at least one group and targeting at leastone user equipment on an individual basis. As explained above, the UE110-M could receive a single paging message having paging informationtargeted to group 190-1, group 190-2, and/or to the UE 110-Mindividually.

In block 320, the network 100 performs the operation of transmitting thepaging indicator at location(s) not based on any group IDs. In block370, the network 100 performs the operations of transmitting pagingmessages in locations in the channel that are based at least in part onone or more group IDs. As described above, one possibility is tocalculate a paging occasion (e.g., for group paging) based on sharedS-TMSI. That is, if a set of n bits are allocated commonly for allgroups by the MME/SGSN, then replace IMSI in the current formula (shownabove for Paging Occasion) to calculate paging occasion with the common10 bits of S-TMSI. Typically, if block 320 is performed, block 370 isperformed, but one may be performed without the other. For instance, thelocation of the paging indicator may be based in part on one or moregroup IDs.

In block 325, the network 100 performs the operation of transmittingpaging indicators for group paging at different locations in channelthan locations for individual paging. That is, the alternate cyclesshown in FIG. 2 may be used, e.g., with the paging indicators for grouppaging and individual user equipment paging transmitted at locationsdefined by Page Indicator formulas described above. In block 380, thenetwork 100 performs the operation of transmitting messages for grouppaging at different locations in channel than locations for individualpaging. For instance, the group and individual paging may be transmittedusing alternate cycles as shown in FIG. 2 and at locations defined byPaging Occasion formulas described above. Usually, if block 325 isperformed, block 380 is also performed, but this is merely exemplary.For instance, the paging indicator for group paging may be sent in theSIB (see block 350).

In block 330, the network 100 performs the operation of transmitting thepaging indicator at particular location in a DRX cycle. This locationmay vary over time according to an algorithm, as described above. Inblock 340, the network 100 performs the operation of transmitting pagingindicator(s) in the same channel (e.g., as part of same cycle) as thepaging information is transmitted. That is, as described above, the PI(comprising the paging indicator) is transmitted in a cycle defined by acorresponding Paging Occasion. In block 350, the network 100 performsthe operation of transmitting the paging indicator for group paging in aSIB. The paging indicator indicates group paging cycle and a grouppaging occasion at which user equipment will find paging information forone or more groups.

FIG. 4 is a block diagram of a method performed by a user equipment forgroup triggering and paging. Although characterized as a method, theoperations performed in FIG. 4 may also be operations performed by anapparatus, operations performed by code on a computer-readable medium,or means for performing the operations. In block 410, the user equipment110 performs the operation of receiving a paging indicator indicating touser equipment assigned to one or more groups that the user equipmentare to attempt to receive one or more paging messages comprising paginginformation targeted to at least one of the one or more groups. In block460, the user equipment 110 performs the operation of receiving in achannel the paging information in the one or more paging messages.Blocks 415-450 are further examples of block 410. Blocks 470 and 480 arefurther examples of block 460.

In block 415, the paging information in the paging message(s) comprisespaging records targeting the at least one group and targeting at leastone user equipment on an individual basis. As explained above, the UE110-M could receive a single paging message having paging informationtargeted to group 190-1, group 190-2, and/or to the UE 110-Mindividually.

In block 420, the user equipment 110 performs the operation of receivingthe paging indicator at location(s) not based on any group IDs. In block470, the user equipment 110 performs the operations of receiving pagingmessages in locations in the channel that are based at least in part onone or more group IDs. As described above, one possibility is tocalculate a paging occasion (e.g., for group paging) based on sharedS-TMSI. That is, if a set of n bits are allocated commonly for allgroups by the MME/SGSN, then replace IMSI in the current formula (shownabove for Paging Occasion) to calculate paging occasion with the common10 bits of S-TMSI. Typically, if block 420 is performed, block 470 isperformed, but one may be performed without the other. For instance, thelocation of the paging indicator may be based in part on one or moregroup IDs.

In block 425, the user equipment 110 performs the operation of receivingpaging indicators for group paging at different locations in channelthan locations for individual paging. That is, the alternate cyclesshown in FIG. 2 may be used, e.g., with the paging indicators for grouppaging and individual user equipment paging transmitted at locationsdefined by Page Indicator formulas described above. In block 480, theuser equipment 110 performs the operation of receiving messages forgroup paging at different locations in channel than locations forindividual paging. For instance, the group and individual paging may betransmitted using alternate cycles as shown in FIG. 2 and at locationsdefined by Paging Occasion formulas described above. Usually, if block425 is performed, block 480 is also performed, but this is merelyexemplary. For instance, the paging indicator for group paging may besent in the SIB (see block 450).

In block 430, the user equipment 110 performs the operation of receivingthe paging indicator at particular location in a DRX cycle. Thislocation may vary over time according to an algorithm, as describedabove. In block 440, the user equipment 110 performs the operation ofreceiving paging indicator(s) in the same channel (e.g., as part of samecycle) as the paging information is transmitted. That is, as describedabove, the PI (comprising the paging indicator) is transmitted in acycle defined by a corresponding Paging Occasion. In block 450, the userequipment 110 performs the operation of receiving the paging indicatorfor group paging in a SIB. The paging indicator indicates group pagingcycle and a group paging occasion at which user equipment will findpaging information for one or more groups.

Embodiments of the present invention may be implemented in software(executed by one or more processors), hardware (e.g., an applicationspecific integrated circuit), or a combination of software and hardware.In an example embodiment, the software (e.g., application logic, aninstruction set) is maintained on any one of various conventionalcomputer-readable media. In the context of this document, a“computer-readable medium” may be any media or means that can contain,store, communicate, propagate or transport the instructions for use byor in connection with an instruction execution system, apparatus, ordevice, such as a computer, with one example of a computer described anddepicted, e.g., in FIG. 1. A computer-readable medium may comprise acomputer-readable storage medium (e.g., memory 125 or 155 or otherdevice) that may be any media or means that can contain or store theinstructions for use by or in connection with an instruction executionsystem, apparatus, or device, such as a computer.

If desired, the different functions discussed herein may be performed ina different order and/or concurrently with each other. Furthermore, ifdesired, one or more of the above-described functions may be optional ormay be combined.

Although various aspects of the invention are set out in the independentclaims, other aspects of the invention comprise other combinations offeatures from the described embodiments and/or the dependent claims withthe features of the independent claims, and not solely the combinationsexplicitly set out in the claims.

It is also noted herein that while the above describes exampleembodiments of the invention, these descriptions should not be viewed ina limiting sense. Rather, there are several variations and modificationswhich may be made without departing from the scope of the presentinvention as defined in the appended claims.

What is claimed is:
 1. A method comprising: transmitting a pagingindicator indicating to user equipment assigned to one or more groups ofa plurality of groups that the user equipment are to attempt to receiveone or more paging messages comprising paging information targeted to atleast one of the one or more groups, wherein the paging indicator is acommon paging indicator for all groups of the plurality of groups, thecommon paging indicator indicating to any user equipment assigned to anyof the groups of the plurality of groups that in addition to legacypaging the user equipment are to attempt to receive one or more pagingmessages comprising paging information targeted to at least one of theone or more groups; and transmitting in a channel the paging informationin the one or more paging messages.
 2. The method of claim 1, whereintransmitting the paging information further comprises transmitting theone or more paging messages in one or more locations in the channel thatare based at least in part on one or more group identificationscorresponding to the one or more groups.
 3. The method of claim 2,wherein transmitting a paging indicator further comprises transmittingthe paging indicator at a location in the channel that is not based onthe one or more group identifications.
 4. The method of claim 1, whereinthe paging information in at least one of the one or more pagingmessages comprises paging records targeting the at least one group andtargeting at least one user equipment on an individual basis.
 5. Themethod of claim 1, wherein transmitting the paging information furthercomprises transmitting the one or more messages at one or more firstlocations in the channel, and wherein the method further comprisestransmitting paging information targeting user equipment on anindividual basis on one or more second paging messages at one or moresecond locations on the paging channel, wherein the one or more secondpaging messages do not contain paging information for any user equipmentassigned to a group.
 6. The method of claim 5: wherein transmitting thepaging information further comprises transmitting the one or more grouppaging locations in first paging cycles; wherein transmitting the secondpaging information further comprises transmitting the one or more secondpaging locations in second paging cycles; and wherein the first pagingcycles and second paging cycles are different.
 7. The method of claim 6,wherein the first paging cycles alternate with the second paging cyclesin a set of the first and second paging cycles.
 8. The method of claim7, wherein the second paging cycles are transmitted at second pagingoccasions, and the second paging occasions are defined by the following:Paging Occasion={(IMSI div K)mod(DRX cycle length div PBP)}*PBP+n*2*DRXcycle length+frame offset, wherein IMSI is an international mobilesubscriber identity for a particular user equipment, K is a parameterlinked to a number of secondary common control physical locations, DRXis discontinuous reception, PBP is a paging block periodicity, n=0,1,2 .. . system frame numbers as long as the system frame number is below amaximum value, and frame offset is preconfigured; and the first pagingcycles are transmitted at first paging occasions, and the first pagingoccasions are defined by the following:Paging Occasion={n}mod(DRX cycle length div PBP)}*PBP+((2*n+1)*DRX cyclelength)+frame offset.
 9. The method of claim 8, wherein: the pagingindicator occupies a first location within the first cycle, the firstlocation defined by a first page indicator; the method further comprisestransmitting a second paging indicator indicating to user equipmentwhether to access the second paging information at the second pagingoccasion, the second paging indicator occupying a second locationdefined by a second page indicator; the second page indicator to use forthe particular user equipment is the following:PI=DRX index mod Np, wherein DRX index=IMSI div 8192 and Np is a numberof page indicators within a corresponding frame; the first pageindicator to use for the particular user equipment is the following:PI=(SFN div 2)mod Np, wherein SFN is system frame number.
 10. The methodof claim 1, wherein transmitting the page indicator further comprisestransmitting the page indicator in a determined location in a pagingindication space in a discontinuous reception cycle.
 11. The method ofclaim 10, wherein the determined location is determined using analgorithm that varies over time the determined location in the pagingindication space.
 12. The method of claim 1, wherein transmitting thepaging indicator further comprises transmitting the paging indicator inthe channel.
 13. The method of claim 1, wherein the paging indicatorfurther indicates that in a current or a subsequent paging cyclecomprising the one or more messages, one or more groups is or are beingpaged in a paging occasion derived from an identity of an addressedgroup instead of an identity of an individual one of the user equipment.14. The method of claim 13, wherein the paging indicator furtherindicates one or more subsets of a plurality of groups to which the oneor more groups that are being paged belong.
 15. The method of claim 1,wherein transmitting the paging indicator further comprises transmittingthe paging indicator in a system information block to user equipment,the paging indicator comprising information indicating a group pagingcycle and a group paging occasion, and wherein transmitting the paginginformation further comprises transmitting the one or more messages inthe group paging occasion within the group paging cycle.
 16. A method,comprising: receiving, at a user equipment assigned to one or moregroups of a plurality of groups, a paging indicator indicating to theuser equipment that the user equipment is to attempt to receive one ormore paging messages comprising paging information targeted to at leastone of the one or more groups, wherein the paging indicator is a commonpaging indicator for all groups of the plurality of groups, the commonpaging indicator indicating to any user equipment assigned to any of thegroups of the plurality of groups that in addition to legacy paging theuser equipment are to attempt to receive one or more paging messagescomprising paging information targeted to at least one of the one ormore groups; and receiving from a channel the paging information in theone or more paging messages.
 17. The method of claim 16, whereinreceiving the paging information further comprises receiving the one ormore paging messages in one or more locations in the channel that arebased at least in part on one or more group identificationscorresponding to the one or more groups.
 18. The method of claim 17,wherein receiving a paging indicator further comprises receiving thepaging indicator at a location in the channel that is not based on theone or more group identifications.
 19. The method of claim 16, whereinthe paging information in at least one of the one or more pagingmessages comprises paging records targeting the at least one group andtargeting at least one user equipment on an individual basis.
 20. Themethod of claim 16, wherein receiving the paging information furthercomprises receiving the one or more messages at one or more firstlocations in the channel, and wherein the method further comprisesreceiving paging information targeting user equipment on an individualbasis on one or more second paging messages at one or more secondlocations on the paging channel, wherein the one or more second pagingmessages do not contain paging information for any user equipmentassigned to a group.
 21. The method of claim 20: wherein receiving thepaging information further comprises receiving the one or more grouppaging locations in first paging cycles; wherein receiving the secondpaging information further comprises receiving the one or more secondpaging locations in second paging cycles; and wherein the first pagingcycles and second paging cycles are different.
 22. The method of claim21, wherein the first paging cycles alternate with the second pagingcycles in a set of the first and second paging cycles.
 23. The method ofclaim 22, wherein the second paging cycles are received at second pagingoccasions, and the second paging occasions are defined by the following:Paging Occasion={(IMSI div K)mod(DRX cycle length div PBP)}*PBP+n *2*DRXcycle length+frame offset, wherein IMSI is an international mobilesubscriber identity for a particular user equipment, K is a parameterlinked to a number of secondary common control physical locations, DRXis discontinuous reception, PBP is a paging block periodicity, n=0,1,2 .. . system frame numbers as long as the system frame number is below amaximum value, and frame offset is preconfigured; and the first pagingcycles are received at first paging occasions, and the first pagingoccasions are defined by the following:Paging Occasion={n}mod(DRX cycle length div PBP)}*PBP+((2*n+1)*DRX cyclelength)+frame offset.
 24. The method of claim 23, wherein: the pagingindicator occupies a first location within the first cycle, the firstlocation defined by a first page indicator; the method further comprisesreceiving a second paging indicator indicating to user equipment whetherto access the second paging information at the second paging occasion,the second paging indicator occupying a second location defined by asecond page indicator; the second page indicator to use for theparticular user equipment is the following:PI=DRX index mod Np, wherein DRX index=IMSI div 8192 and Np is a numberof page indicators within a corresponding frame; the first pageindicator to use for the particular user equipment is the following:PI=(SFN div 2)mod Np, wherein SFN is system frame number.
 25. The methodof claim 16, wherein receiving the page indicator further comprisesreceiving the page indicator in a determined location in a pagingindication space in a discontinuous reception cycle.
 26. The method ofclaim 25, wherein the determined location is determined using analgorithm that varies over time the determined location in the pagingindication space.
 27. The method of claim 16, wherein receiving thepaging indicator further comprises receiving the paging indicator in thechannel.
 28. The method of claim 16, wherein the paging indicatorfurther indicates that in a current or a subsequent paging cyclecomprising the one or more messages, one or more groups is or are beingpaged in a paging occasion derived from an identity of an addressedgroup instead of an identity of an individual one of the user equipment.29. The method of claim 28, wherein the paging indicator furtherindicates one or more subsets of a plurality of groups to which the oneor more groups that are being paged belong.
 30. The method of claim 16,wherein receiving the paging indicator further comprises receiving thepaging indicator in a system information block, the paging indicatorcomprising information indicating a group paging cycle and a grouppaging occasion, and wherein receiving the paging information furthercomprises receiving the one or more messages in the group pagingoccasion within the group paging cycle.
 31. A method, comprising:sending a group paging request message to user equipment assigned to oneor more groups of a plurality of groups that the user equipment are toattempt to receive one or more paging messages comprising paginginformation targeted to at least one of the one or more groups, thegroup paging request message including a device trigger notification asan indication to cause the user equipment to read device triggerinformation in a message in a system information block, the devicetrigger information including a common paging indicator for all groupsof the plurality of groups, the common paging indicator indicating toany user equipment assigned to any of the groups of the plurality ofgroups that in addition to legacy paging the user equipment are toattempt to receive one or more paging message comprising paginginformation targeted to at least one of the one or more groups; andsending the device trigger information in the message in the systeminformation block, the message including at least one command for theuser equipment.